Patchouli (Pogostemon cablin) is a member of the mint family. The patchouli plant, or Pogostemon cablin, is an upright, bushy, evergreen perennial herb with lightly fragrant leaves, and white, violet-marked flowers. (Bown D. The Herb Society of America New Encyclopedia of Herbs and Their Uses. London: Dorling Kindersley Ltd.; 2001; Leung A Y, Foster S, eds. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics. 2nd ed. New York: John Wiley and Sons, Inc; 1996.) Native to tropical Asian countries, patchouli is widely cultivated all over the tropics and subtropics including Indonesia, the Philippines, Malaysia, India, southern China, Seychelles, and Brazil. (Bown 2001; Leung 1996; Oyen L P A, Dung N X, eds. Plant Resources of South-East Asia: No 19—Essential-oil plants. Bogor, Indonesia: Prosea Foundation; 1999).
Patchouli oil is conventionally distilled from fermented leaves. (Keville K, Green M. Aromatherapy: A Complete Guide to the Healing Art. Freedom, Calif.: The Crossing Press; 1995.) Other Pogostemon species as well as similar species produce inferior oils. (Bruneton J, ed. Pharmacognosy, Phytochemistry, Medicinal Plants. 2nd ed. Paris: Lavoisier; 1999.) The best quality oil is produced from plant materials harvested near plantations where there is less chance of damage to plant materials prior to processing. (Grieve M. A Modern Herbal. Vol. 2. New York: Dover Books; 1971.) Patchouli oil scent has staying power and is perceptible for weeks or months. (Arctander S. Perfume and Flavor Materials of Natural Origin. Carol Stream, Ill.: Allured Publishing Corporation; 1994; Tucker A O, Debaggio T. The Big Book of Herbs. Loveland, Colo.: Interweave Press; 2000) At high concentrations, patchouli scent can be sickeningly sweet, but a strong aroma is a sign of superior quality. (Arctander 1994; Yen K Y. The Illustrated Chinese Materia Medica: Crude and Prepared. Taipei, Taiwan: SMC Publishing Inc; 1992.)
Patchouli has a long history in southern Asia and the Far East as incense, body and garment perfume, and insect and leech repellent. (Oyen 1999) Ink in China and India was once perfumed with patchouli. (Oyen 1999; Arctander 1994).
The major use for patchouli oil is in perfumery. It is also an ingredient in toiletries, cosmetics, breath fresheners, incense, insecticides, disinfectants, and commercial food flavoring. (Bown 2001) Patchouli is one of the most widely used ingredients in perfumes (Leung 1996) and is often the fundamental note in oriental-type perfumes. (Oyen 1999) It is employed as a fragrance component in cosmetic preparations, soaps, and hair removal creams (Leung 1996) because of its masking effect on noxious odors. (Oyen 1999) Patchouli was used in a breath freshener popular during Prohibition called Sen-Sen. (Arctander 1994)) It is a pest deterrent used to keep wool moths out of Indian shawls and rugs. (Keville 1995) Patchouli essential oil is used in flavoring chewing gum, baked goods, and candy, (Facciola S. Cornucopia: A Source Book of Edible Plants. Vista, Calif.: Kampong Publications; 1990) nonalcoholic and alcoholic beverages, desserts, puddings, meat and meat products. (Leung 19946) It has recently been added to low-tar cigarettes and tobacco for flavor. (Oyen 1999) Fresh leaves are sometimes used as seasoning (Yen 1992) and added to potpourri. (Bown 2001)
Historically patchouli has been used to reduce appetite, water retention, exhaustion, and inflammation (Keville 1995) and is said to be a good tonic for veins. (Schnaubelt K, Beasley J M, trans. Advanced Aromatherapy: The Science of Essential Oil Therapy. 1st ed. Rochester, Vt.: Healing Arts Press; 1998.). It has cosmetic and skin uses as a cell rejuvenator and antiseptic. (Keville 1995) It has traditionally been used to treat acne, eczema, inflamed, cracked or mature skin, dandruff, athlete's foot, varicose veins, hemorrhoids, and impetigo. (Bown 2001; Keville 1995) Patchouli has been used for emotional disorders such as nervousness, depression, insomnia, and has also been employed as an aphrodisiac. (Keville 1995) In the East, patchouli oil has been used to prevent spread of infection (Bown 2001) due to its antifungal and antibacterial properties. (Buckle J. Clinical Aromatherapy: Essential Oils in Practice. Philadelphia: Elsevier Science; 2003) In traditional Chinese medicine, patchouli is used in combination with other herbs to provide relief for colds and flu, fever and chills, headache, nausea, vomiting, diarrhea, abdominal pain, malarial and dysenteric disease, and bad breath. (Leung 1996; Tucker 2000).
In aromatherapy, patchouli oil is utilized as a relaxant (Oyen 1999) for nervous exhaustion, depression, stress-related complaints, and low libido. (Bown 2001). In one study, inhaling patchouli essential oil produced a decreased response in the sympathetic nervous system; it lowered systolic blood pressure. (Haze S, Sakai K, Gozu Y. Effects of fragrance inhalation on sympathetic activity in normal adults. Jpn J Pharmacol. 2002 November; 90(3):247-253.)
Essential oils are highly concentrated substances extracted from various parts of aromatic plants and trees. These oils are the result of secondary metabolism of the plant and they form the very basis of the flavor and fragrance industry. The aromatic plants and oils have been used for thousands of years dating back to ancient civilizations that used them to heal, enhance, soothe and excite the body and spirit.
Nikiforov et al; discloses that (−)-patchoulol is the predominant odor component of patchouli oil by using chiral phase gas chromatography combined with a ‘sniffing-technique’. (Nikiforov et al; 1986 (±)-Patchouli alcohol, the dominant odor component of the patchouli oil; Chemical Monthly 117(8) 1095-1098).
With an increasing trend for preference of natural products, demand for natural fragrances and flavorings such as patchouli continues to grow, despite market competition by synthetic substitutes which have the advantages of lower production costs, stable pricing and regular supply. There is no natural method employed for increasing the patchulol content in dried leaves. Essential oil extracted from Pogostemon sp. with higher patchulol content is highly valued. Most of the sources generate oils having moderate (35-42% w/v) concentrations of patchulol content.
Patchouli oil is extracted by steam distillation of non-fermented dried leaves of Pogostemon cablin. It is dark yellow or orange colored viscous oil (Specific gravity: 0.970-0.990 at 15° C.), having strong fixative properties.
Conventional extraction for patchouli oil includes steam distillation and carbon dioxide (CO2) extraction methods.
It is well known to those skilled in the art that a slight increase in alcohol content is obtained when extracted oil is added to microbial culture and allowed to undergo biotransformation. However, the chances of reduction in yields and formation of byproducts increases in such process. The process is not economically feasible since the maximum oil concentration that can be added, as a substrate for biotransformation is limited due to toxicity problems.
Conventional techniques for increasing the patchulol content in patchouli oil by way of biotransformation is done by subjecting the substrates such as extracted components and also the whole oils to microbial or enzymatic action for alterations in their compositions. However, biotransformation technique is associated with drawbacks. By-product formation and the toxicity posed by the substrate and product to the microbial cells reduces the process effectively. Due to the significant presence of the by-products, the process steps to remove these products decreased the yield of the patchouli oil. Continuous agitation during biotransformation may cause volatilization of essential oil components resulting in lower product formation.
Looking to the need of the hour, the inventors have developed an improved process for increasing the patchulol content with the help of specific microbial cultures isolated from the soil. The reaction occurs under specific conditions of temperature and moisture.
As disclosed in U.S. Pat. No. 4,037,609, tobacco was subjected under controlled conditions, to the action of a microorganism effective to degrade nicotine through a biochemical reaction in which 3-succinoylpyridine formation was detected. Prior to subjecting the tobacco to the action of the microorganism, the tobacco is steamed to increase its moisture content. Tobacco treated in accordance with this process, when incorporated into a tobacco-smoking product, produces a mild smoke, having reduced nicotine content. However, there is no loss of desirable flavor, taste and smoking properties. Moreover, U.S. Pat. No. 4,037,609 does not teach the use for enhancing the aromatic oil quality. The present invention relates to subjecting the naturally occurring material to microbial action under controlled conditions resulting in the increase of the patchouli oil content.
In accordance with the present invention there is provided a commercially viable process for increasing the patchulol content with the help of specific microbial cultures isolated from the soil. The present invention also provides no significant alteration in the oil yields, while the odor or aroma is enhanced due to the increased alcohol content. The present invention aims to focus on the use of microbial cultures and has provided optimal conditions for increasing the alcohol content during the extraction of the oil from dried leaves of Patchouli.